qt4: fix incorrect pkg-config files

qt4: fix incorrect pkg-config files

* Previously, include statements were generated like this:
  -I.../mipsel-oe-linux/usr/include/qtopia/QtCore
  -I.../mipsel-oe-linux/usr/include/qtopia/QtCore/qt4-embedded/QtCoreE
  -I.../mipsel-oe-linux/usr/include/qtopia/QtCore/qtopia

* The sed rules ignored QT_LIBINFIX.
* The sed rules incorrectly used QT_BASE_NAME instead of QT_DIR_NAME.

* Now, they look like this, which is what an application expects:
  -I.../mipsel-oe-linux/usr/include/qtopia/QtCore
  -I.../mipsel-oe-linux/usr/include/qtopia

* Tested with qt4-embedded on mipsel

Signed-off-by: Andreas Oberritter <obi@opendreambox.org>
CC: Koen Kooi <k.kooi@student.utwente.nl>
Acked-by: Koen Kooi <koen@openembedded.org>